Hydraulic control device

ABSTRACT

A hydraulic device for controlling supply lines to a tool workhead. Conduit means are provided for connecting a handactuated pliant sealed chamber with pressure-responsive means for controlling the flow in the supply lines. A foot-actuated pliant sealed chamber is similarly provided for controlling the supply lines to a plurality of workheads.

United States Patent 1191 Ricks Oct. 22, 1974 1 HYDRAULIC CONTROL DEVICE 3,188,0ll 6/1965 Tcrnullo 251/57 3,568,3l8 5/1969 [76] Inventor: Melvm l). RlCkS, l()l7 l l Bac1t1g 3638680 H1972 -7 Glendale- Calif- 91202 3673.709 7 1972 Page 32 22 [22] Filed: Sept. 11, 1972 Primary Examiner-Robert Peshock [21] Appl' 287820 Attorney, Agent, or FirmHurris, Kern, Wallen &

Related U.S. Application Data Tinsley [63] Continuation of Ser. No. 77,939, Oct. 5. l97() abandoned. which is u continuution-in-purt of Scr. N0. 769.218. Oct. 21, 1968. [57] ABSTRACT A hydraulic device for controlling supply lines to a [52] U.S. Cl. 32/27, 251/57 tool wOl-khead Conduit means are provided f [51] Ill. Cl. A61C 1/10 nccting a hand actuated pliant Sealed Chamber with [58] Field of Search 257/57; 137/635, 376; pressure responsive means for controlling the flow in 200/1529; 32/DIG' 26 the supply lines. A foot-actuated pliant sealed chamher is similarly provided for controlling the supply [56] References cued lines to a plurality of workheads.

UNITED STATES PATENTS 3.067.765 12/1962 Aymur 61 .11. 32/1310. 3 17 Clams l1 Drawmg F'gures PAliminnmzzmm mums HYDRAULIC CONTROL DEVICE This is a continuation of application Ser. No. 77,939, filed Oct. 5, i970, and now abandoned, which is a continuation-in-part of my copending application Ser. No. 769,218, filed in the name of Melvin Ricks, on Oct. 21, 1968, and entitled Dental Hand Piece Speed Control.

The subject invention relates generally to hydraulic devices and more particularly to a device for controlling supply lines of a tool workhead, such as in connection with a dental handpiece having on its workhead a fluid-driven motor and various nozzles.

Tool workheads have been designed for and are actually capable of performing a myriad of functions, so long as the tool workhead is operated with skill, sensitivity, and dispatch by the operator. However, successful operation of the tool hasbeen severely inhibited by cumbersome devices for controlling the supply line to the workhead. This is particularly a problem with hand tools such as dental handpieces where the operator is required to regulate the speed of a motor on the dental handpiece, for example, while at the same time coordinating the position of a rotating burr or the like in the patients mouth.

The problem is further complicated when a single workpiece incorporates more than one supply line. For example, a dental handpiece often includes three separate supply lines; one for the air turbine of a fluiddriven motor, another for chip air, and still a third for a coolant such as water. The problem becomes compounded when a tool operator uses a plurality of tool workheads in the course of performing his task. For example, most dentists employ two or three separate handpieces having low speed, medium speed, and high speed capabilities (e.g. 500,000 rpm), respectively, as well as other handpieces such an an ultra-sonic cleaner for removing tartar and scale from teeth.

Initially, in connection with dental handpieces as well as other apparatus involving multiple workheads and supply lines, each individual workhead or supply line often had its own separate control button, lever, or the like, which was operated by either the hand or foot. Thus, a tool operator had to become familiar and adept at locating and using the right button for the right tool, workhead or supply line. In most situations, it was highly undesirable to have to interrupt the concentration of the operator merely because it was necessary to actuate a different workhead or supply line. Moreover, where a hand tool such as a dental handpiece was concerned, the quality of work was directly dependent upon the ability of the tool operator or dentist to use his hands exclusively for the skillful manipulation of workhead(s) and related materials.

Solution of the foregoing problems arising from multiple foot controls was sought by connecting a single foot pedal in parallel with a plurality of workpieces. Various electrical switching devices such as relays, solenoids, or the like, were employed to sever the connection between the single foot pedal and the particular workpieces which were not in use. However, such switching devices have proved to be unduly expensive and do not always provide trouble-free performance. In addition, even though the foot pedal was capable of actuating any one of the workheads, it was extremely cumbersome to use since it usually included only a single pedal mounted on a movable extension cord which had to be kicked by the tool operator from one location to another to keep the pedal in the vicinity of one of the operators feet. Moreover, when it was in the right location, it was depressible only in a single direction, usually vertically downward, this requiring the operator to support his body on one foot and/or otherwise restrict his body position so that by flexing the foot muscles, the pedal could be either depressed or released.

It should also be noted that cumbersome prior art foot controls as described were particularly inconvenient where the operators foot had to constantly actuate the pedal. This type of operation occurs where the flow through a workhead supply line varies according to the foot pressure on the control pedal, (e.g., varying speed of a dental drill) as distinguished from an on-off type of operation requiring only periodic actuation of a button or pedal.

Solution of the aforementioned problems insofar as hand tools are concerned was also sought by placing a control button or the like on the workhead handle itself, so that grasping the workhead in ones hand automatically positioned the hand and fingers near the control button. However, like the prior art foot pedals, all of the prior art controls on the handle itself required specifically directed manual pressure on a small actuation area, such as pushing a button, depressing a lever, turning a nob, or the like. Where the hand holding the workhead is required to guide its position duing the performance of the work involved, as with a dental handpiece, it is extremely disruptive and detracts from the quality of the work to have to move the hand and/or fingers to a small actuation area and then effect manual pressure or force in a specified direction. This drawback occurs to a lesser degree where the button requires only periodic actuation to turn a supply line on or off, and to a much greater degree where the button requires constantly varied manual pressure to control the flow in a supply line.

More specifically, when a dentist is moving his hands to various positions on the dental handpiece to properly position a burr or the like against a patients tooth, repositioning of the hands for adjustment of a control button, lever, screw, or the like, is very interruptive and distractive and therefore adversely affects the quality of the work being done on the teeth.

Finally, it is to be noted that both the foot and hand types of prior art control devices lacked suitable and effective means for controlling each of the supply lines independent of one another.

Accordingly, it is a general object of the invention to eliminate the foregoing deficiencies of the prior art, and to provide a hydraulic control device which allows precise instantaneous control over each individual workhead, as well as each supply line thereof without interfering with the simultaneous positioning of the workhead.

A more specific object is to provide a control device for supply lines of a tool workhead wherein manual pressure exerted on any portion of a pliant chamber located on a handle for the workhead controls the supply line, notwithstanding the position of the fingers. A related object is to provide a foot control device which is already positioned in the vicinity of the operators treading area, thus eliminating the need to kick or otherwise move the foot control to a new position whenever the operator moves his feet to a new position.

Another object is to provide a device having the aforementioned characteristics which includes a hydraulic system for regulating the flow rate through the supply lines to the workhead so that pressure exerted by a hand or foot on pliant chambers at the extremities of the system is transferred to pressure-responsive means for controlling the supply lines.

Another object is to provide a control device having the aforementioned characteristics wherein manual pressure applied in any direction controls the supply lines. A related object is to enable the use of any combination of lateral and vertically downward pressures of a foot to control the supply lines.

An additional object is to provide a control device having the aforementioned characteristics wherein the pliant chamber includes a large surface area, any portion of which is susceptible and sensitive to the various manual and foot pressures of the tool operator in connection with controlling the flow rates in the supply lines to the workhead. A further object is to provide a device having the aforementioned characteristics which enables a tool operator to simultaneously control the supply lines of a tool workhead by either a footactuated or a hand-actuated control device.

Still a further object is to provide a device having the aforementioned characteristics which automatically disconnects a workhead from the foot-actuated control device when the workhead is not in use.

Another object is to provide a device having the" aforementioned characteristics which includes valve means for removably connecting a plurality of workheads to a single foot control member such that the connection or disconnection of a particular workhead with the foot control member is accomplished solely by inexpensive mechanical elements, thereby eliminating the need for electrical elements in the valve means.

Yet another object is to provide a control device for a dental handpiece which includes a closed pliant chamber completely encircling a portion of the dental handpiece, so that manipulation of any part of the pliant chamber affects the flow rate through supply lines to the workhead.

Still another object is to provide a control device for a dental handpiece having an air nozzle, a coolant nozzle, and a fluid-driven motor on its workhead, each having a separate supply line, wherein the control device includes pressure-responsive means for controlling the flow in each supply line. A related object is to provide valve means for commencing the flow through each supply line at a different time.

A further object is to provide a control device for a dental handpiece which includes a closed pliant chamber affixed to the floor surrounding a dentists chair such that lateral or downward pressures, or combinations thereof, anywhere on the outer surface of the pliant chamber regulates the flow through the supply lines to the dental handpiece.

Yet another object is to provide a control device having the aforementioned characteristics which can be controlled by routine natural flexing of either the hand or foot muscles no matter what the position of the hands or feet. A related object is to eliminate the need to familiarize the feet and/or hands with an arbitrary unnatural location or position in order to effectively and efficiently control the supply lines to the workhead. Another related object is to provide for precise continuous foot and hand control over the supply lines without unduly interfering with the positions of the hands and feet in otherwise operating the tool workhead.

Still a further object is to provide a device of the aforementioned characteristics which is inexpensive to manufacture and install, which is easily adaptable for use with any conventional tool, hand tool, workhead, dental handpiece, or the like, and which provides inexpensive troublefree performance.

Further objects, features and advantages of the invention will be evident to those skilled in the art from the following description of various embodiments and alternative forms of the invention.

In the drawings:

FIG. 1 is a diagrammatic view of an embodiment of a hydraulic control device in connection with a dental handpiece having a fluid-driven motor thereon, with portions thereof broken away and shown in cross section;

FIG. 2 is an end elevational view of a portion of the device of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 33 of FIG. 1;

FIG. 4 shows another embodiment of a device without any electrical components and wherein an air nozzle is supplied directly from a fluiddriven motor supply line and a coolant nozzle is supplied through a separate supply line;

FIG. 5 is a close-up partial-sectional view of a portion of the embodiment of FIG. 4;

FIG. 6 shows an alternative form of FIG. 5;

FIG. 7 is a cross-sectional view taken along line 77 in FIG. 4;

FIG. 8 shows an alternative embodiment having separate supply lines for a fluid-driven motor, an air nozzle, and a coolant nozzle;

FIG. 9 is a sectional view of a valve designed for use in connection with the embodiment of FIG. 8;

FIG. 10 shows an alternative to the valve of FIG. 9; and

FIG. 11 is a partially diagrammatic view of an embodiment of the device employing a foot-actuated pliant chamber in connection with a plurality of dental handpieces.

Generally speaking, the hydraulic control device incorporates a tool having a workhead 3 capable of any of a variety of operations. Supply lines 4 are provided to carry diverse materials, fluids, liquids, electrical current, energy or the like to the workhead, all according to the specific tool and workhead being used. The operation of the workhead 3 is a direct result of the instantaneous flow through the supply lines 4. Accordingly, specific control over the supply lines results in ultimate control over the workhead itself. In this regard, the invention enables a tool operator to utilize an improved hydraulic control system to operate the tool by providing both a hand-actuated pliant chamber 5 and a footactuated pliant chamber 6 (FIG. 11). Pressureresponsive means designated generally as 7 is provided for controlling the rate of flow through lhe supply lines. In order to effectively transfer any actuation of either pliant chamber 5 or 6, the device includes conduit means for connecting the pliant chambers with the pressure-responsive means.

It will therefore be appreciated that an operator of any tool incorporating the invention can effectively, efficiently and precisely control operation of the workhead 3 by manual manipulation of the hand-actuated pliant chamber S and/or by similar contraction or expansion of the foot-actuated pliant chamber 6, all as described in more detail hereinafter.

Referring particularly to FIGS. 13, a particular embodiment of the invention is shown in connection with a fluid-driven hand tool, such as a dental handpiece of the type having an air turbine drive motor 8 on the body of the dental handpiece to drive a drill or other tool. Air to operate the turbine is supplied under pressure through a supply line such as a bendable tube 9 from an air source 10. The bendable tube 9 runs from the turbine drive motor 8 on the workhead 3 through the body of the handpiece and through a bendable covering 11 to the air source 10. In series with the bendable tube 9 is a valve 12 which is capable of shutting off the air supply to the turbine or restricting the air flow therethrough, thus'regulating the speed of the air turbine drive motor 8.

The valve 12, in this exemplary embodimenncanbe actuated by any of several types of solenoid or electrically operated devices which open and close as a functrolling the fluid-driven motor, and that the pressureresponsive means is sensitive to manipulation of any portion of the hand-actuated pliant chamber wrappe around the body of the dental handpiece.

In order to adjust the sensitivity of the illustrated embodiment of FIGS. l-3, there is provided a movable plunger 40 which slides inside a calibrated tube 42. The tube 42 is integral with a body member 43 which houses-the reservoir 25 and the interior of the tube is in communication with the reservoir. Various positions of the plunger within the tube will vary the air pressure within the reservoir, thus changing the amount of water pressure which must be exerted on the mercury to cause the mercury to ascent into the tubular bore 22.

tion of the electrical input thereto. The illustrated form is a solenoid-actuated valve which is operable in steps according to the voltage applied. A battery 14, or other power source, is placed in series with a voltage divider 16 and a solenoid 18 associated with the valve 12. Each of a plurality of series-connected resistors 19 in the voltage divider 16 has connected to each of its ends means 20 for establishing electrical connection to the interior of a tubular bore 22 in a barrel 23. The bore 22 is in communication with a reservoir 25 partially filled with mercury 24, or other electrically conductive fluid material. Placed above the mercury in the reservoir 25 is aquantity of water 26 or other fluid, preferably one which is substantially noncompressible, which In the description of otherembodiments of the invention, like numbers are used to indicate parts which are substantial duplications of those'shown in FIGS. 1, 2, and 3.

Referring now to the embodiments of FIGS. 4, 5, and 7, another dental handpiece is shown-having a workhead 3 at its forward end which carries a fluid-driven motor such as the air turbine motor 8, a coolant nozzle f 47, and an air nozzle 49. The invention is particularly water also fills a bendable tube 27 connected at its one end to the reservoir 25.

. The other end .of the water-filled tube 27 passes through a casing 29 of the hand tool and terminates inside the hand-actuated pliant chamber 5, as for example, in an enclosed annular chamber 30. The chamber 30 preferably comprises an outside flexible and springable tubular sleeve 32 coaxial with the center-line axis of the dental handpiece and securely sealed around the perimeter of each of its ends to the outside surface of the handpiece casing 29 and a foreward casing neck 33, respectively. The core of the chamber 30 is formed by a rigid tube 34 passing longitudinally through the center of the body of the dental handpiece and through which the air passes which furnished energy to motivate the air turbine drive motor 8.

In operation, pressure applied to the flexible tubular sleeve, preferably made of soft plastic, rubber, or the like, will displace water from the chamber 30 and will cause an immediate increase in water pressure in the reservoir 25 which in turn increases the pressure on the mercury 24 so as to make the mercury rise in the tubular bore 22 in much the same manner as in a thermometer. As the mercury rises in the bore 22 and comes into contact with the electrical connecting means 20, the resistors 19 are successively shorted out resulting in a higher voltage applied across the terminals of the soleadaptable for use with such a conventional dental handpiece. The body of the particular dental handpiece illustrated is similar to the one shown in FIGS. I-3, and is formed by a long cylindrical metal shell which includes the casing 29 at its rearward end and the forward casing neck 33 which carries the air turbine motor 8. Between the casing 29 andthe neck 33, the body of the'handpiece narrows to form the end and inner boundaries for the hand-actuated pliant chamber 5, the outer boundary being defined by the flexible sleeve 32. 7

Any part of the body member may serve as a handle which the dentist may grasp while positioning the workhead in a patients mouth. Thus, the casing 29 and the casing neck 33 may be considered as handles, with the prise a single handle with the chamber 30 situated on the handle as a part of it. In either case, it will be appreciated by those skilled in the art, and particularly practicing dentists, that whatever task is being performed, and whatever the position of the hand or hands upon the body of the dental handpiece, the pliant member 5 is easily accessible for manipulation without disrupting, delaying, or interfering with the positioning of the workhead in the patients mouth.

Of course, hand-actuated pliant chambers can be designed in any size-or shape and placed in any position near or directly on a handle of any tool, all within the spirit of the present invention. Moreover, the restrictions on size, shape, and location would be substantially less stringent for a tool in which the handle was remote from rather than integral with the workhead. In this particular embodiment of FIGS. 4, 5, and 7, and similarly in the embodiment of FIGS. 1-3, both of which involve a hand tool having a workhead and handle on the same bodymember, it is preferable to completely encircle a portion of the body and the supply lines therein with the ring-shaped annular chamber 30. It is found that an annular chamber about 2 inches long provides sufficient surface area to allow the necessary manipulation during operation of the dental handpiece. This allows the fingers or hand of the dentist to remain in almost constant contact with the flexible sleeve 32 operating the dental handpiece was facilitated. Even.

though the outsidediameter of the pliant chamber is therefore determined by the outside diameter of the particular handle being used (about /2 inch), it has been found that an annular chamber 30 with a distance between the sleeve 32 and the tube 34 of about /1 inch as shown at 51 is sufficiently large to provide a substantial volume differential between a normal expanded position and a manually contracted position.

All of the supply lines 4 to the workhead 3 pass inside the rigid tube ,34 which acts as a core of the annular chamber 30. Thus, as shown in FIGS. 4 and 7, the air tube 9 passes through the covering 11, the casing 29, the rigid tube 34, and the neck 33 to the air turbine motor 8. In this instance, air for the air nozzle 49 is transported through a tube 53 connected to the air turbine tube 9 at 55 inside the neck 33. Thus, air begins to be expelled from the air nozzle 49 at the same time that the air turbine motor 8 begins to rotate, both drawing from the same common supply line. A separate bendable tube 57 is provided for the coolant, and passes through the covering 11, the casing 29, the rigid tube 34, and the neck 33. Both the coolant tube 57 and the air tube 53 emerge from the underside of the neck 33 and pass through a conventional mounting clip 59 to their respective nozzles 47, 49.

In view of the foregoing, it is apparent that the supply lines 4 passing to the workhead 3 do not interfere with or restrict the manipulation of the annular chamber 30.

This is accomplished by having the annular chamber 30 at least partially overlay the supply lines, thus enabling the hand or fingers of the operator to directly contact the flexible sleeve 32. In the preferred form, it was found that the manipulation area defined by the flexible sleeve 32 was maximized by providing a rigid tube 34 for housing all of the workhead supply lines 4, so that the annular chamber 30 completely overlies the supply lines in every direction. Therefore, as best shown in FIG. 7, the flow of air to the air turbine motor 8 and the nozzle 49 through the tube 9 and the flow of coolant to the nozzle 47 thorugh the tube 57, as well as the flow of motor exhaust back through unoccupied space 61 (FIG. 7) in the rigid tube 34 to an exhaust port 63, all occur without interfereing with the manipulation of the hand-actuated pliant chamber 5.

It is an important feature of the invention to provide an actuating surface which is sensitive to manual pressure or force exerted in any direction. The handactuated pliant chamber 5 is particularly helpful here since it is designed, particularly in its elongated ring configuration, to be sensitive to manual force or pressure exerted in any direction anywhere on the sleeve 32. In other words by incorporating a substantially noncompressible fluid like water as a hydraulic fluid inside the closed annular chamber 30, any external force directed against the annular chamber causes it to contract, thereby immediately increasing the pressure therein. v

In this regard, it is noted that the annular chamber 30 is an enclosed compartment having a single opening 65 located in its rearward end plate which communicates through the tube 27 with an expandable chamber, shown in the exemplary form as bellows 71- (see FIG. 5). A fixed end 73 of the bellows 71 is suitably mounted to a conventional bracket 75, and a movable end 77 of the bellows 71 is mechanically coupled through a lever 79 to a pin 81 of a variable flow spool valve 83, such as a Meade Microline spool valve. Accordingly, any increased externally applied force on the sleeve 32 of the annular chamber 30, independent of its direction or point of application, is immediately transferred in the form of increased pressure through the hydraulic fluid to the bellows member 71 which upon expansion proportionately opens the spool valve 83. A discussed hereinafter, the spool valve 83, or variations thereof (FIGS. 9-10), regulates directly or indirectly the flow through each of the supply lines 4 or more particularly the flow to the air turbine drive motor 8, the coolant nozzle 47 and the air nozzle 49.

It will be understood that the proportional factor of the device must be variable in order that a predetermined manual contraction of the hand-actuated pliant chamber 5 causes a desired corresponding opening of the spool valve 83. In the illustrated form, such variation might be accomplished by conventional hydraulic apparatus 84 for regulating the amount of hydraulic fluid in and for removing air from the system. In addition, variation is accomplished by pivotally mounting one end 85 of the lever 79 on the spool valve 83, and coupling the movable end 77 of the bellows 71 to the other end 87 of the lever, and disposing the pin 81 to contact the lever at a point between its ends, thereby establishing a proportional factor between the. bellows 71 and the spool valve 83 of less than one. Of course, a simple one-to-one relationship results when the movable end 77 and the pin 81 are the same distance from the pivot, while a proportional factor greater than one results from positioning the movable end 77 between the pin 81 and the pivot. In any given device embodying the invention, increasing the proportional factor would increase the range capabilities of the particular pliant chamber being used. Onthe other hand, decreasing the proportional factor would improve the precision capabilities of the pliant chamber. Of course, it is to be understood that by varying the size and/or shape of any or all of the various elements involved the pli ant chamber 5, the bellows 71, the lever 79, and the spool valve 83 it is possible to achieve optimum conditions of both range and precision for any tool, thus further illustrating the capabilities and adaptability of the invention.

The spool value 83 receives fluid, such as air under pressure, from the air source 10 through a fitting and inlet port 89 into the spool valve chamber anddispenses air from the chamber through an outlet port 91 at a rate porportional to the displacement of the pin 81. In the illustrated device, the air is supplied at a pressure of about 60 pounds per square inch and is dispensed at pressures ranging from 060 pounds per square inch. Air being supplied from the outlet port 91 to the air turbine drive motor 8 passes through a limiting valve 93 which prevents undue air pressure which might damage the particular motor being used. In this embodiment the limiting valve 93 is set for about 35 pounds per square inch maximum pressure, and communicates through a fitting to the tube 9 which connects with the air nozzle 49 and the air turbine motor 8. Air is also supplied from the outlet port 91 through a connecting tube 97 to an on-off valve 99 for controlling the flow of coolant from a source 101 through the tube 57 to the coolant nozzle 47. Under normal conditions, it is desir able for the coolant to commence its flow at about the time there is sufficient air pressure (e.g., 35 pounds per square inch) to start the air turbine motor 8. Hence, the valve 99 is designed to open when the air pressure in the tube 97 reaches 3-5 pounds per square inch, thereby enabling water and air to be expelled simultaneously by the nozzles 47, 49 to form a cooling mist on the work surface at the same time the air turbine motor 8 commences rotation of a burr or the like against the work surface.

In actual operation, with the spool valve 83 biased in a normally closed position, it will be appreciatd from the foregoing description that manual force exerted in any direction on the flexible sleeve 32 will serve to diminish the volume of the annular chamber 30 and force hydraulic fluid through the tube 27 into the bellows 71. The resulting expansion of the bellows 71 partially opens the spool valve 83 to achieve variable control of the flow of air through the supply line to the air turbine motor 8 and the air nozzle 49 and independent on-off control of the flow of coolant through the supply line to the coolant nozzle 47.

Of course, it is within the spirit of the invention to provide similar independent control over a plurality of on-off valves to control the flow of other materials through separate supply lines. Moreover, by substituting a variable flow valve in place of the on off valve 99, it is also possible to obtain independent control over the rate of flow of coolant or the like being supplied to the workhead through a separate supply line.

In many instances it is desirable to initiate the flow of air or the like through one supply line before a similar flow is initiated in a second supply line. In the illustrated form, it is often desirable to be able to have a flow of chip air expelled through the nozzle 49 to remove any debris or foreign objects in the tooth work area before commencing operation of the air turbine motor 8 or expelling any coolant from the nozzle 47. In this regard, FIG. 8 shows a sectional view of a body portion of a dental handpiece which includes a separate bendable tube 103 which passes through the body of the dental handpiece and inside the rigid tube 34 to the neck 33 where it connects through the supply line 53 to the air nozzle 49. FIGS. 9 and each shows a modified valve which can be used as a replacement for the conventional spool valve 83 in order to accomplish this initial flow of chip air through the tube 103.

For example, in FIG. 9, the movable end 77 of bellows 71 contacts the upper portion of a valve shaft which is biased in a raised, normally closed position by a spring 107. The shaft extends into a cylinder 109 and carries a spool-type head having lower and upper plug members 111, 1 13 sized to snugly fit inside the cylinder and provide a sealed compartment 114 therebetween. The plug members 111, 113 are separated by a bypass rod 115 having a diameter substantially less than the diameter of the cylinder. In its normally closed position, the spool-type head is in a raised position, so that air is supplied through a fitting and inlet port 117 to the compartment 114, but is prevented by the lower plug member lllfrom passing out of the compartment into an outlet port 119 in the wall of the cylinder 109 at a level below the inlet port 117. Upon gradual manipulation of the hand-actuated pliant chamber 5, the bellows 71 expands 'so that its movable end 77 depresses the shaft until the lower plug 111 finally passes below the outlet port 119, thereby allowing air to flow into the compartment 114, around the bypass rod 115, and through the outlet port 119. A motor outlet 121 is at an even lower level and remains closed by the lower plug member 111. Upon further manipulation and contraction of the hand-actuated pliant chamber 5, the shaft is depressed even further so that the lower plug 111 partially exposes the motor outlet 121 to allow some air to flow to the air turbine motor 8, while full flow is being maintained through the outlet port 119 to the air nozzle 49. From this point on, further contraction of the pliant chamber causes a proportional increase in the exposed portion of the motor outlet 121 and the flow of air therethrough, similar to the action of the aforementioned spool valve 83. The bypass rod is long enough so that the upper plug 113 does not ever reach a position adjacent any of the three ports.

In the form of FIG. 10, the cylinder 109 has an upper portion 123 and a lower portion 125 of larger diameter. The valve shaft includes the usual spool-type head defining the closed compartment 114, but also carries a tapered plug member 127 on the lower end of a second bypass rod 129 such that when the valve is in its normally closed position, the tapered plug 127 fits up against the junction between the two differently sized cylinder portions 123, 125 to provide a compartment 132 sealed against air supplied to the lower portion 125 through an inlet fitting 131. Upon initial depression of the shaft, the tapered plug 127 is displaced downward, thereby breaking the seal and allowing air to pass into the compartment 132, by the second bypass rod 129, and out through a chip air outlet port 133 in the adjacent cylinder wall. The lower plug 111 prevents any air from passing back through an auxiliary inlet passage 135 into the compartment 1 14 in the upper portion 123 of the cylinder 109. However, upon further depression of the shaft, the lower plug 111 finally begins to expose the auxiliary inlet passage 135 and a motor outlet 137 at the same level in the cylinder wall, thus beginning the flow of air to the air turbine motor 8 at a rate proportional to the contraction of the pliant chamber 5.

It will be appreciated that although the specific valve designs of FIGS. 9 and 10 are particularly adaptable for commencing operation of the air nozzle 49 ahead of and independent of the coolant nozzle 47 and air turbine motor 8, the invention contemplates any such valve device which provides independent on-off or variable flow control over each separate supply line independent of each other, and proportional to the manipulation of a pliant chamber. In the exemplary forms, such adaptibility is available by varying the relative sizes, shapes and spacings of the cylinder, its inlet and outlet ports, and the plug members and bypass rods on the valve shaft.

In each of the foregoing examples, the expandable compartment of the hydraulic system has been identified as the bellows 71. Of course, the invention is not restricted to that particular form. For example, in the alternative form of FIG. 6, the closed expandable member includes an outer cylinder member 139 fixedly mounted on a bracket 141 and communicating at its upper end with the tube 27. A movable piston 143 is sized to snugly fit inside the lower end of the cylinder 139. Any increased force or pressure on the handactuated pliant chamber causes an influx of fluid into the sealed compartment thereby impelling a connecting rod 144 of the piston 143 against the lever 79 to depress the pin 81 which opens a control valve such as 83. The amount of opening is proportional to the force exerted on the pliant chamber, as previously described.

it is an important feature of the invention to provide a foot-actuated pliant chamber 6 which can be used simultaneously or interchangeably with the handactuated pliant chamber 5.

In this regard, as shown in FIG. 11, a foot-actuated pliant chamber 6 in the form of an elongated tubular chamber 145 is shown on the floor around the base of a dental chair 147 adjacent the treading area of the dentist, whether sitting or standing.

The particular shape, tube configuration, and dental chair environment shown are only illustrative, since it will be appreciated, as with the hand-actuated pliant chamber 5,that the foot-actuated pliant chamber 6 is adaptable for use with any tool. Accordingly, it is to be understood that all of the aforementioned description respecting the function, capabilities, and variations of a hand-actuated pliant chamber are applicable here and do not need repeating. Needless to say, critical factors to consider in designing the size, shape and configuration of a foot-actuated pliant chamber 6 are the treading area of the operator, the position of the foot required to effectively perform tool operations (other than controlling the supply lines to a workhead), the availability of both feet, whether the operator is sitting or standing, and the like. However, it should be noted that in the preferred foam, the tubular chamber 145 has flexible springable top 149 and lateral surfaces 151 for engagement by the foot of a tool operator such as a dentist. Thus, increased hydraulic pressure in the tubular chamber 145 results from any external force exerted in any direction on the large actuation area comprised by the top 149 and lateral surfaces 151 of the tubular chamber 145. Of course, as with the handactuated pliant chamber 5, the spring bias or other restraint on the expandable member of the hydraulic system must be less than the threshold force required to expand the flexible material such as soft plastic, rubber, or the like of the tubular chamber 145. Otherwise, the increased hydraulic pressure would only change the shape of the tubular chamber 145. The tubular chamber 145 can be connected to the floor by any conventional attachment, such as clamps 152. One end of the foot-actuated pliant chamber 6 communicates through a pipe or tube 153 to the pressure-responsive means 7 for controlling the supply lines 4, and, for simultaneous control with the hand-actuated pliant chamber 5, such communication can be made through a connection to the tube 27, as at 154 (see also FIG. 4).

Where a plurality of workheads is involved, as when a dentist has two or three dental handpieces 155, the invention enables a dentist or other tool operator to use the foot-actuated pliant chamber 6 for each workhead. More specifically, each handpiece 155 is provided with its own pressure-responsive means unit shown schematicaly at 157, such that manipulation of the hand-actuated pliant chamber 5 on one handpiece actuates the pressure-responsive means associated with that unit to control its supply lines. When a handpiece 155 is not in use, it is removably inserted in its appropriate place on a stand 159 supported by suitable arm supports 161. Conventional notch members 163 are provided for engaging the casing 29 of each handpiece 155, each notch member being mounted above and coupled with a related on-off valve 165 connecting the tube 153 with the appropriate pressure-responsive means 157.

The weight of the handpiece 155 in its notch member 163 serves to close its related valve 165, severing the connection between the tubular chamber and the pressure-responsive means 157 associated with that particular handpiece. Of course, it would also be possible to employ a single pressure-responsive means 157 connected through a plurality of valves such as 165 so that the weight of the handpiece actuates its associated valve to sever the supply lines of that particular workhead. Either structure provides the necessary valve means for temporarily preventing control over the supply lines of a workpiece which is not in use.

The foregoing structure thus provides a way to independently control any of a plurality of workheads by a unique foot-actuated pliant chamber 6 without having to employ the expensive and complicated electrical switching devices of the prior art. It also enables one to control any of a plurality of workheads by alternating or simultaneous operation of a foot-actuated pliant chamber and a hand-actuated pliant chamber.

Although exemplary embodiments of the invention have been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiments disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention.

1 claim as my invention:

1. A control device for a tool comprising:

a tool workhead;

a supply line connected to said workhead;

pressure-responsive means for controlling said supply line;

handle means for manually gripping said tool during its operation;

a hand-actuated pliant chamber on said handle means; and

first conduit means connecting said hand-actuated chamber with said pressure-responsive means whereby manipulation of said hand-actuated chamber controls said supply line.

2. The device of claim 1 including:

a foot-actuated pliant chamber; and

second conduit means communicating with said footactuated chamber for connecting said footactuated chamber with said pressure-responsive means.

3. The device of claim 1 wherein:

said workhead is attached at one end of said handle means;

said handle means includes a plurality of supply lines connected to said workhead;

said hand-actuated chamber partially overlays said supply lines; and wherein said pressure-responsive means controls said plurality of supply lines.

4. The device of claim 1 wherein said pressureresponsive means includes:

valve means connected to said supply line for controlling the rate of flow in said supply line;

an expandable compartment communicating with said first conduit means and having a fixed end and a movable end; and

means for mechanically coupling said movable end to said valve means.

5. A dental handpiece comprising in combination:

a body member;

fluid driven motor means carried by said body member;

fluid supply passages carried internally of said body member;

a pliant fluid chamber member wrapped around said body member and adapted to carry a fluid therein;

pressure-responsive means for controlling the said fluid driven motor; and

conduit means interconnecting the pliant chamber and said pressure-responsive means.

6. A control device for regulating the operation of a tool comprising:

valve means for controlling the supply of fluid to a fluid operated motor;

means for controlling the valve means and operably connected to said valve means;

an enclosed pliant chamber filled with a relatively noncompressible fluid; and

means responsive to changes in pressure of the said noncompressible fluid and operably connected to the said controlling means, said responsive means comprising a plurality of series connected electrical resistance elements disposed along a closed tubular path and a reservoir of mercury communicating with said tubular path.

7. The combination of claim 6 wherein said controlling means comprises:

an electrical solenoid connected to said valve;

an electrical power source; and

means connecting said solenoid, battery and resistance elements in series. .8. A control device for a tool comprising:

a hand-held tool workhead;

a supply line connected to said workhead;

pressure-responsive means for controlling the flow in said supply line; a pliant chamber with fluid therein mounted adjacent a foot of an operator of said tool; and

conduit means connecting said pliant chamber with said pressure-responsive means whereby fore applied to the pliant chamber by the foot of said operator contracts said pliant chamber causing increased fluid pressure on said pressure-responsive means, thereby controlling the flow in said supply line.

9. The device of claim 8 wherein said pliant chamber includes a tubular member having flexible upper and lateral surface for engagement by a foot of said operator, and wherein said device further includes means for mounting said tubular member on the floor to extend along and adjacent to the treading area of said operator.

10. The device of claim 8 including:

a plurality of hand-held workheads;

support means for removably securing each of said workheads when not in use; and

wherein said pressure-responsive means includes valve means for temporarily preventing said pressure-responsive means from controlling the flow in the supply line to an individual workhead whenever said individual workhead is secured by said support means.

11. In a tool having a body member with a workhead, supply lines connected to said workhead, and handle means for manually gripping said body member, an improved control device compsiring:

a pliant chamber on said body member containing a fluid and positioned adjacent said handle means; pressure-responsive means for controlling the flow in said supply lines; and

conduit means connecting said pliant chamber with said pressure-responsive means whereby manual pressure exerted on said pliant chamber is transferred through the fluid to said pressure-responsive means, thereby controlling the flow in the said supply lines.

12. The device of claim 11 wherein said pressureresponsive means includes valve means for effecting on-off flow control over one supply line and variable flow control over another supply line.

13. In a dental hand tool having a body member which carries a workhead at its forward end, said workhead including a fluid driven motor, a coolant nozzle, and an air nozzle, and wherein said body member includes supply lines connected to said workhead and handle means for manually gripping said body member, an improved hydraulic control device comprising:

a pliant hollow ring encircling a portion of said body member and said supply lines, and containing a substantially noncompressible fluid;

pressure-responsive means for controlling the flow in said supply lines; and

conduit means for connecting said hollow ring with said pressure-responsive means whereby manual pressure exerted on said ring controls said supply lines.

14. The device of claim 12 wherein said pressureresponsive means includes valve means for opening the supply line for the air nozzle and simultaneously closing the supply lines for the fluid driven motor and the coolant nozzle.

15. The device of claim 1 wherein said hand-actuated pliant chamber on said handle means constitutes a sealed chamber.

16. The device of claim 8 wherein said pliant chamber constitutes a closed chamber.

17. In a dental hand tool having a body member which carries a workhead at its forward end and which includes a supply line connected to said workhead and handle means for manually gripping said body member, an improved control device comprising:

a pliant hollow ring encircling a portion of said body member and said supply line and containing a fluid;

pressure-responsive means for controlling the flow in said supply line; and

conduit means for connecting said hollow ring with said pressure-responsive means whereby manual pressure exerted on said ring controls said supply line. 

1. A control device for a tool comprising: a tool workhead; a supply line connected to said workhead; pressure-responsive means for controlling said supply line; handle means for manually gripping said tool during its operation; a hand-actuated pliant chamber on said handle means; and first conduit means connecting said hand-actuated chamber with said pressure-responsive means whereby manipulation of said hand-actuated chamber controls said supply line.
 2. The device of claim 1 including: a foot-actuated pliant chamber; and second conduit means communicating with said foot-actuated chamber for connecting said foot-actuated chamber with said pressure-responsive means.
 3. The device of claim 1 wherein: said workhead is attached at one end of said handle means; said handle means includes a plurality of supply lines connected to said workhead; said hand-actuated chamber partially overlays said supply lines; and wherein said pressure-responsive means controls said plurality of supply lines.
 4. The device of claim 1 wherein said pressure-responsive means includes: valve means connected to said supply line for controlling the rate of flow in said supply line; an expandable compartment communicating with said first conduit means and having a fixed end and a movable end; and means for mechanically coupling said movable end to said valve means.
 5. A dental handpiece comprising in combination: a body member; fluid driven motor means carried by said body member; fluid supply passages carried internally of said body member; a pliant fluid chamber member wrapped around said body member and adapted to carry a fluid therein; pressure-responsive means for controlling the said fluid driven motor; and conduit means interconnecting the pliant chamber and said pressure-responsive means.
 6. A control device for regulating the operation of a tool comprising: valve means for controlling the supply of fluid to a fluid operated motor; means for controlling the valve means and operably connected to said valve means; an enclosed pliant chamber filled with a relatively noncompressible fluid; and means responsive to changes in pressure of the said noncompressible fluid and operably connected to the said controlling means, said responsive means comprising a plurality of series connected electrical resistance elements disposed along a closed tubular path and a reservoir of mercury communicating with said tubular pAth.
 7. The combination of claim 6 wherein said controlling means comprises: an electrical solenoid connected to said valve; an electrical power source; and means connecting said solenoid, battery and resistance elements in series.
 8. A control device for a tool comprising: a hand-held tool workhead; a supply line connected to said workhead; pressure-responsive means for controlling the flow in said supply line; a pliant chamber with fluid therein mounted adjacent a foot of an operator of said tool; and conduit means connecting said pliant chamber with said pressure-responsive means whereby fore applied to the pliant chamber by the foot of said operator contracts said pliant chamber causing increased fluid pressure on said pressure-responsive means, thereby controlling the flow in said supply line.
 9. The device of claim 8 wherein said pliant chamber includes a tubular member having flexible upper and lateral surface for engagement by a foot of said operator, and wherein said device further includes means for mounting said tubular member on the floor to extend along and adjacent to the treading area of said operator.
 10. The device of claim 8 including: a plurality of hand-held workheads; support means for removably securing each of said workheads when not in use; and wherein said pressure-responsive means includes valve means for temporarily preventing said pressure-responsive means from controlling the flow in the supply line to an individual workhead whenever said individual workhead is secured by said support means.
 11. In a tool having a body member with a workhead, supply lines connected to said workhead, and handle means for manually gripping said body member, an improved control device compsiring: a pliant chamber on said body member containing a fluid and positioned adjacent said handle means; pressure-responsive means for controlling the flow in said supply lines; and conduit means connecting said pliant chamber with said pressure-responsive means whereby manual pressure exerted on said pliant chamber is transferred through the fluid to said pressure-responsive means, thereby controlling the flow in the said supply lines.
 12. The device of claim 11 wherein said pressure-responsive means includes valve means for effecting on-off flow control over one supply line and variable flow control over another supply line.
 13. In a dental hand tool having a body member which carries a workhead at its forward end, said workhead including a fluid driven motor, a coolant nozzle, and an air nozzle, and wherein said body member includes supply lines connected to said workhead and handle means for manually gripping said body member, an improved hydraulic control device comprising: a pliant hollow ring encircling a portion of said body member and said supply lines, and containing a substantially noncompressible fluid; pressure-responsive means for controlling the flow in said supply lines; and conduit means for connecting said hollow ring with said pressure-responsive means whereby manual pressure exerted on said ring controls said supply lines.
 14. The device of claim 12 wherein said pressure-responsive means includes valve means for opening the supply line for the air nozzle and simultaneously closing the supply lines for the fluid driven motor and the coolant nozzle.
 15. The device of claim 1 wherein said hand-actuated pliant chamber on said handle means constitutes a sealed chamber.
 16. The device of claim 8 wherein said pliant chamber constitutes a closed chamber.
 17. In a dental hand tool having a body member which carries a workhead at its forward end and which includes a supply line connected to said workhead and handle means for manually gripping said body member, an improved control device comprising: a pliant hollow ring encircling a portion of said body member and said supply line and containing a fluid; pressure-responsive means for contRolling the flow in said supply line; and conduit means for connecting said hollow ring with said pressure-responsive means whereby manual pressure exerted on said ring controls said supply line. 